Control governor for fluidoperated pumps



March 18, 1952 c. J. COBERLY 2,589,668

CONTROL GOVERNOR FOR FLUID-OPERATED PUMPS Filed May 5, 1947 F'JC)[A/vE/vToR:

CLARENCE J. COBERLY By H15 ATTORNEYS HA RR/S, Mach, ESTER :3 HA R/P/S ia u M Patented Mar. 18, 1952 CONTROL GOVERNOR FOR FLUID- OPERATED PUMPSClarence J. Coberly, Los Angeles, Calif., assignor, by mesneassignments, to Dresser Equipment Company, Cleveland, Ohio, acorporation of Ohio Application May 5, 1947, Serial No. 746,112

14 Claims.

This invention relates to the pumping art and more particularly to amethod and governing apparatus for controlling the operation offluidoperated pumps in wells and like bodies of liquid in which the pumpis immersed.

My invention has particular application to the oil industry and will bedescribed in connection therewith, but other applications will beobvious and I do not intend to be limited to that particular usage.

In the operation of oil wells it is common practice to install in thewell a fluid-operated pump having a fluid motor to which operating fluijis pumped through a supply conduit from a pumping unit situated at theground surface, the oil from the well being forced to the surfacethrough a production conduit usually enclosing the supply conduit so asto leave an annular passage for the well product therebetween. Suchfluidoperated pumps are ordinarily operated at relatively great depth inoil wells, und r. conditions not observable at the ground surface, andrequire means for governing their rate of operation which are automaticin action and preferably situated as close as possible to the pump so asto be immediately responsive to conditions existing there. Fluctuationsin the pumping load may cause the pump to race when the load lightensand to incur hydraulic shock when the load returns, and to prevent suchracing, shock, and

other detrimental effects, governor mechanisms 3 may be provided in thesupply conduit conveying operating fluid to the pump immediatelythereabove which will control the rate of flow to the .fiuid motor andprevent it from exceeding a safe limit of speed.

In my Patents No. 2,119,736, issued June 7, I

such pressure diiferential being dependent on the rate of flow of theoperating fluid through the control orifice, and in turn being relatedto the pump load. Such governors act responsively to the effect upon thegovernor produced by the racing of the pump rather than responsivelytothe cause for racing and, consequently, cannot be efiective untilracing of the pump is actually started, which may be detrimental to themechanism of the pump or to the operation of the pumping system.

Various factors may afiect the pump load, such as the entry of gasbubbles into the pump along with the oil, or a change in the hydraulichead or priming load on the intake side of the pump. Such factors mayexist simultaneously and apply cumulatively, or act individually, aswhen gas enters the foot of the well casing at the pump level andmomentarily forces the oil in the casing upwardly. In such an event thepressure of the hydraulic head would be constant or even increase at thepump level, and yet gas instead of oil would enter the pump. To controlthe operation of well pumps in accordance with the pressure of thehydraulic head, I have devised a governor, disclosed in my copendingapplication Serial No. 747,233, filed May 10, 1947, in which a pilotvalve is operatively connected to a member responsive to pressure in thewell casing and in turn opens and closes a main valve as the pressure inthe casing increases and decreases within a predetermined range. Such agovernor, however, is not efiective to prevent racing of the pump in theevent of gas entering the pump while suffic ent liqu d is in the casingto maintain the pressure at which the pilot valve is held open, andfurthermore is sensitive to surging of liquid in the well casing whichmay have no direct detrimental effect upon the pump, but may .cause thegovernor unnecessarily to reduce the rate of pumping. None of thedevices hereinbefore referred to meets all of the operating conditionshereinbefore described.

t is, therefore, a primary object of my invention to provide a methodofcontrolling the operation of a fluid-operated pump in which the rate ofoperation of the pump is regulated both in accordance with the depth ofthe liquid in the well in which the pump is immersed, as indicated bythe pressure of that liquid, and in accordance with the load upon thepump, as indicated by the pressure of the operating fluid going to thepump.

It is a, further object of my invention to provide a flow governingdevice for the operating fluid of a. fluid-operated pump which isresponsive both to external pressure conditions indicative ofapproaching detrimental operating conditions and to internal pressureconditions indicating that detrimental conditions presently exist at thepump.

It is another object of my invention to provide a governor which willgradually reduce the rat of pumping of a Well pump as the liquid levelin the well falls and will immediately reduce the rate of pumping if thepump begins to A further object of my'invention is toprovide aceaeee agovernor of the class described which is relatively nonresponsive tosudden surges of short duration in the liquid level of the liquid to bepumped, but is effective to maintain the liquid level at a safeoperating mean.

Still another object of my invention is to provide a governor of theclass described which will respond automatically to increases in thedepth of the liquid to be pump-ed so as to increase the rate of pumpingto the maximum for which the input of operating fluid is capable, andwhich in the event of further increase in the depth of the liquidbecomes receptive to gradual increases in the rate of input of operatingfiuid.

Another object of my invention is to provide a governor of the classdescribed having an orifice for controlling the flow of operating fluidwhich is automatically limited in area by pressure conditions in theliquid to be pumped, but which may be restricted within the limit soimposed so as to prevent an increase in flow therethrough such as mightbe caused by a pressure drop at the outlet of the governor,independently of the aforesaid pressure conditions.

Other objects and advantages will appear in the following specificationand in the drawing,

in which:

, Fig. 1 is a diagrammatic view, partly in section,

of my invention installed in a well;

Fig. 2 is a vertical sectional view of my invention showing the valvesthereof in partly opened,

or throttling, position;

' a casing head I 3 provided at its upper end.

Suspended from the casing head I3 is a production tubing l5 havingsecured at its lower end an intake check valve member 22 provided withan intake opening 24 communicating with a conical pump seat 20 adaptedto receive in seating relation the lower tapered end of a fluid-operatedpump !8. The intake check valve member 22 is so arranged in the intakeopening 24 as to permit well fluid to flow into the fluidoperated pump18, but to prevent a reverse flow thereof. The fluid-operated pump ismay be of any'suitable type, but I prefer to use a fluidoperated pumpsuch as shown in my above Patent No. 2,119,736, to which reference ishereby made for the details of construction thereof.

For illustrative purposes, a body of well liquid 2| is shown within thewell casing 19, having a surface level I1, and it will be understoodthat the liquid 2| is to be pumped by the pump I3 and that the surfacelevel 11 will var in height above the intake opening 24 according to therelative rates of influx through the well casing l9 and of output of thepump l8.

Connected to the upper end of the fluid-operated pump I8 is an inlettubing it to which is connected the flow governor 23 of my invention ata height normally below the surface level H. Connected to the upper endof the flow governor 23 is a string of supply tubing !2 which extendsthrough the casing head 13 to a surface pumping mechanism I! of anysuitable type adapted to pump operating fluid, such as clean oil, underhigh pressure downwardly through the supply tubing E2, the flow governor23, and the inlet pipe It to the fluid-operated pump l8 to actuate thesame. Also connected to the casing head I3 and communicating with theproduction tubing [5 is a discharge pipe l0 adapted to convey fluiddischarged therethrough to a point of discharge or use (not shown).

A special coupling It connects upper and lower units of the productiontubing 15 at the level of the flow governor 23 and has, between saidupper and lower units, an inwardly extending thickened portion 38forming a guide surface 40 of sufiicient diameter to allow the pump 8 topass downwardly therethrough to rest upon the conical pump seat 26, andfitting slida'bly upon a housing 34 which encases the hereinafterdescribed members of the governor 23. Vertical passages 42 in thethickened portion 38 of the special coupling l4 connect the interiors ofthe upper and lower units of the production tubing l5 and permit thepump 8 to pump liquid upwardly past the housing 3:1.

The housing 34 comprises an upper coupling member 28 threadedly securedto the supply tubing I2, and a lower coupling member 86 threadedlysecured to the inlet tubing 16, the coupling members 23 and 86 beingthreadedly secured to each other, and the upper coupling member 28 beingexternally proportion-ed to fit closely in the thickened portion 38 ofthe special coupling [4. The upper coupling member 23 has a coaxial bore49, in the upper part of which is disposed a cylinder 33 housing abellows member 36 of the type known as a Sylphon and longitudinallyexpansible and contractible in response to decrease and increase or"external pressure. The lower coupling member has a coaxial bore 64housing a cylinder 7 3, which is proportioned externally to leave anannular passage 18 between its outer surface and the inner surface ofthe coupling member 86 and is threadedly secured to a downward extension5B of the upper coupling member 28 of reduced diameter. A cylinder head88 is threadedly secured in the lower end of the cylinder 14 and isprovided with an extension 98 closely fitting within a guide collar 96formed on the inner surface of the lower coupling member 86. The guidecollar 93 serves to keep the cylinder 14 in alignment within the bore 64to maintain uniform width of the annular passage 18.

The bellows member 36 is secured, as by soldering, to a head 29 which isthreadedly secured to the cylinder 33 and to the upper coupling 28 andis provided with a nut extension 25 by which the cylinder 33 and thebellows member 36 contained therein may be detached from the housing 34by application of a suitable wrench. The head 29 has a bore 23 forming acheck valve chamber 3| in which is a ball check 3?), and the bore isclosed by a threaded plug 21, which may be removed to permit the bellowselement 36, to be filled with gas at a desired pressure, the ball check30 retaining the gas while the plug 21 is being replaced. At its lowerend the bellows member 36 is secured, as by soldering, to a plunger 44proportioned to provide a working space 45 within the cylinder 33 topermit expansion and contraction of the bellows member 36. The plunger44 has secured to it a rod 5| which extends downwardly with a closesliding fit through a guide collar 53 formed on the lower face of thecylinder 33.

'Thelower end ofthe bore -49 of the upper coupling 'member 28 is-closedby a cylinder head member 56 which forms also the head for the upper endof thecylinder 14. Fitting slidably Within the lower part of the bore 49is a hollow plunger-52 adapted to be limited in its upward movement byengagement with the cylinder 33 and in its downward movement byengagement of the plunger head 54 with the cylinder head 56, and urgedtoward the latter position by a spring 56 reacting against the cylinder33. The lengths of the rod 5| and plunger 52 are such, and theexpansibility' of the bellows member 36 is so proportioned thereto, thatthe rod 5| makes contact with the inner face of the plunger 52 and holdsthe plunger head against the cylinder head56'when the bellows member 36is expanded, and may lose contact with the plunger 52 when the bellowsmember 36 is contracted, depending upon forces hereinafter explainedtending to raise the plunger 52 in follow-up of the rod 5|, with thesleeve 51 limiting the extent of such follow-up by making contact withthe cylinder 33.

The cylinder head 56 is provided with an axial bore'adapted to receiveslidably a metering orifice member 6| formed by a sleeve extendingdownwardly from the lower face of the plunger 52 and having V-notchesnarrowing upwardly in its walls. When the plunger 52 is in contact withthe cylinder head 56, these V-notches are closed by the cylinder head,and as the plunger is raised, the V-notches extend above the cylinderhead into the bore 49, thus forming a variablearea metering orifice 63opening thereinto. The walls of the upper coupling member 26 contain aplurality of vertical passages 32 leading from the supply tubing l2 tothe interior of the cylinder 14 below the cylinder head 56, and aplurality of radial passages 59 leading from the bore 49 to the annularpassage 18. Passage for operating fluid is thus provided from the supplytubing l2 to the annular passage 18 and regulated bythe degree ofopening of the variable-area metering orifice 63. High pressureoperating fluid is-thus brought to bear against the lower face of themetering orifice member 6|, tending to raise the plunger 52 and to passthrough the metering orifice 63 with a consequent pressure drop,creating a pressure differential across the orifice. The plunger 52 hasa helical groove 55 formed on its outer surface and providing arestricted, twoway communication between the lower face of the plungerand the space 46 above and within the sleeve. 55 are filled withoperating fluid, a dash-pot action is imposed on the plunger 52retarding the movement thereof. As will be apparent, during downwardmovement of the plunger 52, fluid may flow from the lower end of theplunger into the space 48 at the upper end thereof through the helicalgroove 55. Conversely, during upward movement of the plunger 52, fluidmay flow out of the .space 48 at the upper end of the plunger by way ofthe helical groove 55.

The cylinder 14 houses a dual valve system 13 for controlling the flowof operating fluid from the annular passage 18 outwardly from thegovernor to the inlet tubing I6 and the pump l8. divides the interior ofthe cylinder into an upper bore 61 and a lower bore l1 and which has acentral guide boss 65 extending upwardly therefrom into the upper bore61 and a lower boss '19 extending downwardly into the lower bore 11. Acontrol piston 66 is fitted slidably in the When the space 46 and thegroove The cylinder 14 has a partition 15 which upper bore 61 .so as'tobe reciprocable therein. and is provided with an orifice '68communicating through the wall of the cylinder 14 with the annularpassage 18. A needle valve 16 is secured to the control piston 66 by avalve stem 62 slidably fitted within the guide :boss 65, so as to bemoved by the piston 66 in .and out of contact with the valve seat formedby the walls of a passage 72 formed in the guide boss 19. A compressionspring 66 is provided below the controlpiston 66 and tends to move it tothe'position shown in Fig. 2, to retain the needle valve 76 in its openposition. The relative strengths of the springs 66 and '56 and therelative areas of the control piston 66 and metering orifice member 6|are such that a somewhat higher pressure differential is required to acton the piston 66 to move it downwardly against the resistance of thespring 66 than is required to act on the metering orifice member 6| toraise the plunger 52 against the resistance of the spring 56.

A main valve piston 86 is slidably fitted in the cylinder 74 below thepartition 15 and has'a sleeve 76 fitting slidably on the guide boss 19and a valve stem 64 extending downwardly through the cylinder head 68.The guide boss 19 has a passage 8| in communication with the passage-l2and communicating with a passage in the valve stem 84 and in the poppethead 69 of a main valve 9|. The poppet head 69 seats on a valve seat 93in the extension 69 of the cylinder head 86, which extension has adischarge passage 99 communicating with the inlet tubing l6. An annularvalve chamber 92 encompassin the poppet head 89 is in communication withthe annular passage 18 through lateral passages 96 in the cylinder head98 and an annular space 94 between the cylinder head 68 and the guidecollar 96. The valve stem 84 fits loosely within the cylinder head 88 soas to provide an annular passage 81 therebetween leading to the interiorof the cylinder 14 below the main valve piston 66. A restricted orifice82 in the piston 86 provides a fluid path from the lower side of thepiston to the upper side thereof, and thence a plurality of passages Hin the guide boss 65 lead to a valve chamber 69 annularly surroundingthe needle valve N. A spring 83, reacting against the partition 15,urges the piston 66 downwardly, tending to hold the main valve 9|closed.

It will be seen that operating fluid from the annular passage 78, thatis, on the downstream side of the metering orifice 63, may flow througha flow channel comprising the annular passage 81, orifice 62, passage H,needle valve chamber 69, and the passages 72 and 6| to the inlet tubingl6 when the needle valve 76 is open. The orifice S2 is so proportionedas to impress a pressure drop on fluid flowing therethrough, and theresulting sharp pressure gradient acting o the piston 36 raises itagainst the resistance of the spring 36 to cause the main valve 9| toopen. As fluid flows through the orifice82 only when the needle valve 76is open, the needle valve acts as a pilot-for the main valve 9|.

As the cylinder 14 is not secured directly to the lower coupling member66 surrounding it, but is only aligned therewith by the extension 98closely fitting within the guide collar 96, the extension 93 is providedwith an annular groove 6? and a sealing ring 65 sealing against theguide collar 96 to prevent leakage from the annular passage 78- to theinlet pipe I6 when the valves 76 and 9| are closed.

The bellows member '36, which, it hasbeen seen,

is capable of preventing the plunger 52 from riswhich therefore, it willbe apparent, is capable of preventing the metering orifice 63 fromopening, is operated by subjecting it externally to the pressureexisting at its level in the well casing IS. The cylinder 33 is providedwith a plurality of radial openings 39 communicating with an annulargroove which registers with radial passages 43 in the upper couplingmember 28. A relatively wide annular channel 41 is formed in the outersurface of the upper coupling member 28 with which the passages 43communicate, and a plurality of radial passages 4| in the specialcoupling l4 complete the channel through which liquid in the well casing|9 may enter the cylinder 33, and the pressure in the well at the levelof the passages 4| may be imposed upon the exterior of the bellowsmember 35. The annular channel 41 provides some leeway in the verticalplacement of the housing 34 relatively to the special coupling I4, in azone determined by placement of the pump l8 on the conical pump seat 20and by the length of the inlet tubing I5. To isolate the passages 43 and4| from the upper and lower units of the production tubing l5, whichwill contain liquid at a higher pressure than the pressure in the wellcasing I9, the outer surface of the upper coupling member 28 is providedwith grooves 3'! above and below the annular channel 41, and the grooves3'! are provided with sealing rings 35 which seal the housing34 to thespecial coupling l4 while permittin relative vertical movement thereofsuch as would be necessary in lowering the governor 23 and the pump I8into position or in raising them for inspection or repair. The interiorof the cylinder 33 is likewise sealed from the operating pressure fluidwithin the space 58 by a sealing ring 45 carried by the base portion ofthe cylinder 33.

Before installation of the governor 23 in a Well, the bellows member 36is charged with a gas permitted by removal of the screw plug 21,following which the screw plug is replaced, as shown. The gas pressurewith which the bellows member 35 is initially charged depends upon thelevel at which the governor 23 is to be installed in a well, as will beapparent to those skilled in the art from the following description ofthe operation of the governor.

In the operation of my invention, if the liquid in the well casing i9 isat a level above the radial passages 4| providing sufficient hydrostaticpressure to compress the bellows member 35 so as to lift the rod fromthe plunger 52 and allow the latter freedom of movement, the action ofthe governor 23 will be controlled by the pressure differential acrossthe metering orifice. High pressure operating fluid, pumped through thesupply tubing l2 and vertical passages 32, will create a high pressurezone in the upper end of the cylinder 14, exerting an upward forceagainst the metering orifice member 5| and a downward force against thecontrol piston 65. The plunger 52 will be lifted by this upward forceagainst the resistance of the spring 50, the retarding action of thefluid in the helical groove 55, and such back-pressure as exists in theannular passage 18. As the needle valve i5 is normally open, thisback-pressure will be the result of operating resistance of the pump l8.Lifting the plunger 52 will open the metering orifice 63 and permitfluid to flow therethrough, creating a fluid pressure differentialacross that orifice. The opening of the metering orifice 63 will takeplace slowly bethrough the helical groove 55, and when the opening issuflicient to bring the pressure diferential across the metering orifice63 in balance with the spring 55 the opening movement will cease.

When the pressure in the annular passage 18 is sumcient to causeoperation of the pump l8, fluid will flow to the pump through theannular passage 81, the orifice 82, and the needle valve 10. Flowthrough the orifice 82 will produce a pressure gradient in the flowchannel thus activated, acting upon the piston 85 and tending to raisethe piston and open the main valve 9| against the resistance of thespring 83. As opening the main valve.9| opens a direct passageto thepump l3 and therefore tends to reduce flow through the needle valve 15,the main valve 9| will seek a balanced position in which it issufiiciently throttled to maintain the flow through the orifice 82,which maintains it in that position. This throttled position of the mainvalve 9| and spring-opened position of the needle valve 10 may be calledthe normal operating position of these two valves, and a pressuredifferential across the metering orifice 63 suflicient to hold themetering orifice member 5| partly open against the spring 55 butinsufficient to close the needle valve 10 may be called the normaloperating pressure differential.

Now, if operating resistance to the pump l8 decreases, as might becaused by gas entering the ential back to its previous balancing degree.If I the increase in the pressure difierential is temporarily sufiicientto cause overbalancing of the spring 55 as it acts upon the controlpiston 60, it will move the needle valve i0 toward closed position andthus throttle the flow through the orifice S2 and cause the main valve9| to move toward closed position. Throttling of thevalves 13 and 9|will restrict the outflow of fluid to the pump l8 and will increase thepressure in the annular passage 18, tending to restore the pressuredifferential across the control valve 6| to normal. Thus all threevalves 6|, T0, and 9| tend to seek a stabilized position and to producea stabilized normal pressure differential and to prevent a suddenoutflow of fluid to the pump l8 such as would cause the pump to race.

On the other hand, a gradual increase in the rate of pumping is notprevented. If it is desired to increase the rate of operation of thepump I8, the rate of pumping of the surface pump may be graduallyincreased. This will cause an increase in pressure on the high pressureside of the metering orifice 53, which will be partly translated to thelow pressure side thereof as an increase in pressure in the annularpassage is due to increa ed back-pressure from the pump l8, and will actpartly to increase the pressure differential acro s the meteringorifice. The increase of the pressure differential across the meteringor fice 53 will cause it to open gradually so as to restore the pressuredifferential-to normal, and this will permit an increased flow to theannular passage 78. The increase in pressure in the annular passage 18will increase the pressure gradient across the orifice 82 and cause themain valve 9| to open wider to permit increased flow to the pump Hi andto restore the pressure diiierential across the control. valve 6| tonormal. If the increase in the rate of pumping of the surface pump ii isso gradual as to permit the metering orifice member 6| and valve 9| tothus-act to restore the pressure differential to normal, without asudden change sufflcient to unbalance the force holding the needle valve1|] open, an increased rate of operation of the pump I 8 may easily beobtained.

, However, if the liquid level in the well casing I9 is so low as toplace external pressure upon the bellows member 36 of less degree thanwill maintain the bellows member in contractedposition against theinternal pressure of the gas charge within the bellows member, that isto say, of less degree than an amount predeterminable as representativeof a satisfactory liquid level in the well casing Hi, the rod will beheld against the upper face of the plunger 52, and freedom of action ofthe plunger in response to changes in the pressure differential acrossthe metering orifice 63 will be prevented. Restrictive action of thebellows member 35 upon the degree of opening of the metering orifice 63imposes a corresponding restriction upon the rate of supply of operatingfluid from the surface pumping unit H which is a function of the amountthat the fluid level in the well casing |9 falls below the predeterminedor desired value. Under the aforesaid restrictive circumstances, anincrease in the pressure differential across the metering orifice 63will not avail to open the same, and it will not respond to tend torestore a normal pressure differential, and if the increase in pressuredifierential is sufiicient to cause the piston oil to move downwardly,the needle valve 10 will move toward throttling position, causing themain valve 9! to move similarly. This action will occur whether theincrease of. pressure differential across the control valve 6| is due toa pressure drop on the downstream side caused by decreased resistance atthepump It, or to an increase in pressure on the upstream side caused byan attempt to increase too fast the rate of pumping.

If the liquid level in the well l9, and thereby the external pressure onthe bellows member 36, falls sufliciently low, the rod 5| will push thecontrol valve 6| to closed position against all effort of the pressuredifferential across the control valve to open it, and this will cut offflow of operating fluid to the pump l8 until the liquid level'in thewell casing I9 is restored to the desired operating level. As thebellows member 36 acts responsively to a change within a range ofpressure rather than abruptly at a certain degree of pressure, and asthe action of fluid in the helical groove 55 at all times presents aresistance to suddenmovements of the plunger 52, a continued fall in theliquid level in the well casing I!) would result in a gradual closing ofthe metering orifice 63 rather than a sudden closing of the same, andthe throttling action on the metering orifice would produce only agradual increase in the pressure differential across the orifice but atan accelerating rate of increase. As the metering orifice member 6|cannot respond under the stated conditions to restore the pressuredifferential to normal, the

pressure differential may increase to an ampli tude actuating the needlevalve 10 to move toward throttling position, piloting the main valve 9|also to throttling position and thus further restricting flow to thepump l8 until-a balance of inflow and will remain within the limitswithin which the needle valve remains open. If the inflow to the wellcasing i9 increases and the liquidlevel therein rises, the bellowsmember 36 will removeits restriction upon the metering orifice memberGI, and in response to a continued risein' the liquid level will permitit to open to the maximum amount at which it can maintain anormalpressuredifierential across the metering orifice 63, as determinedby the input and outflow'of operating fluid existing at the moment.

It will thus be seen that as the needle valve 10 is free at all times toact in response to forces affecting its control piston 60, it will actpromptly whenever called upon by those forces so as to prevent the pumpl8 from racing, whether the liquid level in the well casing I9 is highOr low. The metering orifice member 6| will,,when permitted by thebellows member 36, act independently of it to allow an increase in flowto the pump l8 and can at all times act to restrict such flow. Thebellows member 36 will prevent increases in flow to the pump when suchincreases are not justified by existing liquid levels in the well casingl9 and will forestall pumping tosuch lowliquid levels that the othermembers of the governor would be required to act to prevent the pumpfrom pumping gas instead of liquid. Gas entering the well casing abovethe pump l8 may cause surging of the liquid level and sudden changes ofpressure, without creating a condition justifying response by thebellows member 36, and the effect of such sudden fluctuations isminimized by the retarding action of the helical groove 55.

Because of the sealed construction afiordedby the sealing rings 35, thegovernor and the pump It may be drawn up to surface level through theproduction tubing |5 without disturbing the special coupling 4 and maybe inspected, repaired, and returned to position. Changes in thepressure charge of the bellows element. 36 may readily be made byremoving the plug 2 and'impressing or removing gas through thecheckvalve chamber 3|, or the cylinder 33, containing the bellowselement and entraining the rod 5|, may be removed from the governor byunscrewing the head 29 from the upper coupling member 28 and a new unitcontaining adiiferent pressure charge or including a rod 5| of differentlength may be installed. V I

It will be noted that correlation of themeter'ing orifice member BI andthe valves 10 and 9|, and of the bellows element 35 and retarding helixgroove 55, depends on correlation of theeifeetive areas of the variouspistons, grooves, orifices, passages, and springs connected with andforming operating parts of said members, and that, for example, thecorrelation of the bellows member 36 to the metering orifice member 6|could be changed with respect to a desired rangeof operation of externalpressure by changing-either the internal pressure of the bellows member,its rigidity, its length, or the length of the rod 5!. Changes in theseareas and forces required to adapt my invention to various usages andoperating conditions will be readily'apparent to one skilled in the art,and do not depart from the spirit of my invention.

It is also to be noted that, although I- have described the invention inconnection with afluidoperated pump installation in which the productiontubing and supply tubing l2 are concentric, making desirable a specialform of coupling [4, the invention can readily be adapted by one skilledin the art for use in connection with a fluid-operated pump installationin which the production and supply tubings are side by side, such as isillustrated in my Patent No. 2,338,903, issued January 11, 1944, simplyby connecting the flow governor 23 in the line of the supply tubing andomitting the coupling Hi from the production tubing. Consequently, I donot desire to be limited to the specific embodiment shown, but desire tobe afforded the full scope of the following claims.

I claim as my invention:

1. In a fluid-operated pumping apparatus for use in wells, thecombination of: a fluid-operated pump adapted to be submerged in wellfluid in a well; supply tubing for conveying a high pressure operatingfluid downwardly through the well to said pump to actuate it; productiontubing for conveying the discharge from said pump upwardly through thewell; governor means in the line of said supply tubing and adapted tocontrol the rate, of flow of operating fluid therethrough, said governormeans including a variable-area metering orifice means adapted toprovide a fluid pressure differential thereacross, a pilot valve, a mainvalve, means for impressing said fluid pressure difierential across saidpilot valve to tend to move said pilot valve. and means for operatingsaid main valve in response to movement of said pilot valve; and meansfor closing said metering orifice in response to a predetermineddecrease in the level of well fluid in the well.

2. In a fluid-operated pumping apparatus for use in wells, thecombination of: a fluid-operated pump adapted to be submerged in wellfluid'in a well; supply tubing for conveying a high pressure operatingfluid downwardly through the well to said pump to actuae it; productiontubing for conveying the discharge from said pump upwardly through thewell; governor means in the line of said supply tubing and adapted tocontrol the rate of flow of operating fluid therethrough, said, governormeans including a variable-area metering orifice means adapted toprovide a fluid pressure differential thereacross, a pilot valve, a mainvalve, means for impressing said fluid pressure difierential across saidpilot valve to tend to move said pilot valve, and means for operatingsaid main valve in response to movement of said pilot valve; and meansfor varying the effective area of said metering orifice in response to apredetermined decrease in the level of well fluid in the well.

I 3. In a fluid-operated pumping apparatus for use in wells, thecombination of a fluid-operated pump adapted to be submerged in wellfluid in a well; supply tubing for conveying a high pressure operatingfluid downwardly through the well to said pump to actuate it; productiontubng concentric with said supply tubing and for conveying the dischargefrom said pump upwardly through the well; collar means in the line ofsaid production tubing and having a lateral fluid passage communicatingbetween the interior and exterior thereof, and having a longitudinalpassage communicating between the upper and lower ends thereof so as topermit said pump discharge to -flow upwardly therethrough; governormeans in the line of said supply tubing and adapted to control the rateof flow of operating fluid therethrough, said governor means includingavariable-area metering orifice means adapted to pro- 12 vide a fluidpressure differential thereacross, a pilot valve, a main valve, meansfor impressing said fluid pressure differential across said pilot valveto tend to move said pilot valve, and means for operating said mainvalve in response to movement of said pilot valve; and means for closingsaid metering orifice in response to a predetermined decrease in thelevel of well fluid in the well, including means connected to saidmetering orifice means and communicating with the fluid pressure in saidlateral fluid passage, and responsive to changes in said fluid pressurein said lateral passage to move said metering orifice means to vary theeffective fluid flow area thereof.

4. In a governor for governing the rate of flow of a high pressure fluidto a fluid-operated pump adapted to be operated below the surface levelof a liquid to be pumped, the combination of means adapted to form afluid metering orifice through which said fluid is adapted to flow so asto impress a fluid pressure differential on said orifice; pilot meansadapted to move in response to variations in said fluid pressuredifferential; main valve means adapted to move in response to movementof said pilot eans and being adapted to control the flow of said fluidthrough the governor; and means responsive to changes in the hydrostaticpressure exerted by said liquid on said governor for varying theeffective fluid flow area of said metering orifice so as to vary saidfluid pressure differential.

5. In a governor for governing the rate of flow of a high pressure fluidto a fluid-operated pump adapted to be operated below the surface levelof a liquid to be pumped, the combination of: means adapted to form afluid metering orifice through which said fluid is adapted to flow so asto impress a fluid pressure diflerential on said orifice, including amovable member adapted to vary the eflective fluid flow area of saidmetering orifice so as to change said pressure differential; pilot meansadapted to move in response to variations in said fluid pressuredifferential; main valve means adapted to move in response to movementof said pilot means and being adapted to control the flow of said fluidthrough the governor; and means connected to said movable member andresponsive to changes in the hydrostatic pressure exerted by said liquidon said governor for moving said movable member.

6. In a device for governing the rate of flow of a high pressure fluid,the combination of: means adapted to form a fluid metering oriflcethrough which said pressure fluid is adapted to flow so as to impress afluid pressure differential on said orifice, including a movable memberadapted to vary the fluid flow area of said orifice; a pilot valve; 2.pilot valve piston connected to said pilot valve; means for impressingsaid pressure differential across said pilot valve piston to control themovement of said pilot valve; a main valve adapted to control the volumeof said fluid flowing through the device; a main valve piston connectedto said main valve; means for impressing a second fluid pressuredifferential across said main valve piston to control the movementthereof, movement of said pilot valve being adapted to vary said secondpressure differential; and means for moving said movable member inresponse to variations in fluid pressure exterior of the device.

7.In a device for governing the rate of flow of a high pressure fluid,the combination of: means adapted to form a fluid metering orificethrough which said pressure fluid is adapted to assesses flow so as toimpress a fluid pressure differential on said orifice, including amovable member adapted 'to vary the fluid flow area of said orifice; apilot valve; a pilot valve piston connected to said pilot valve; meansfor impressing said pressure diiferential across said pilot valve pistonto control the movement of said pilot valve; a main valve adapted tocontrol the volume of said fluid flowing through the device; a mainvalve piston connected to said main valve; means for impressing a secondfluid pressure diiferential across said main valve piston to control themovement thereof, movement of said pilot valve being adapted to varysaid second pressure differential; and fluid pressure responsive meansoperatively connected to said movable member and communieating with theexterior of the device, and being responsive to variations in fluidpressure exterior of the device to move sa d movable member.

8. A flow governing device adapted to be installed in the line of twoconcentric tubings in a well, including: an outer tubular member adaptedto be connected in the line of the outer of said tubings, said tubularmember being provided with a lateral port communicating between theinterior and exterior thereof; a tubular housing adapted to be connectedin the line of the inner of said tub ngs and adapted to be receivedwithin said tubular member in fluidtight re ation therewith, saidhousing having an annu ar channel on the periphery thereof adapted toregister with said lateral port, and having a fluid passagecommunicating between the interior of said housing and said channel;variable-a ea metering orifice means in said housing through which saidpressure fluid is adapted to flow to impress a first fluid pressuredifferent al on said orifice, incIuding a movable member adapted to varythe effective area of said orifice; main valve means in said housing andadapted to control the flow of said fluid therethrough in response tovariations in said pressure differential; and pressure-responsive meansin said housing and connected to said movable member. saidpressure-responsive means communicating with said fluid passage wherebya variation in the fluid pressure in said passage causes movement ofsaid pressure-responsive means.

9. A flow governing device adapted to be installed in the line of twoconcentric tubings in a well, including: an out r tubular member ada tedto be connected in the line of the outer of said tubings. said tubularmember being provided with a lateral port communicating between theinterior and exterior thereof; a tubular housing adapted to be connectedin the line of the inner of said tubings and adapted to be receivedwithin said tubular member in fluid-tight relation therewith, saidhousing having an annular channel on the periphery thereof adapted toregister with said lateral port, and having a fluid passage communicatng between the interior of said housing and said channel; variable-areametering orifice means in said housing through which said pressure fluidis adapted to flow to imoress a first fluid pressure differential onsaid orifice, including a movable member adapted to vary the effectivearea of said orifice; main valve means in said housing and adapted tocontrol the flow of said fluid therethrough, said main valve means beingmovable in response to variations in fluid pressure differentialthereacross; pilot means movable in response to variations in said firstpressure diiferential to vary said pressure differential across saidmain valve means; and

pressure-responsive means in said housing andconnected to said movablemember, said pressure-' responsive means communicating with said fluidpassage whereby a variation in the fluid pressure in said passage causesmovement of said pressure-responsive means.

10. In a governor for regulating the rate of flow of an operating fluid,the combination of: metering orifice means having a variable effectiveflow area and adapted to produce a pressure diiferen tia1 in response toflow therethrough; means exposed to fluid pressure obtaining exteriorlyof the governor for varying the effective flow area of said meteringorifice means so as to vary said pressure diiferential; and controlvalve means actuable by said pressure differential for regulating therate of flow of the operating fluid, said control valve means being inseries with said metering orifice means so that the operating fluidflows through both said control valve means and said metering orificemeans.

11. In a governor for regulating the rate of flow of an operating fluid,the combination of: a first valve adapted to produce a pressuredifferential in response to flow therethrough; means responsive to fluidpressure obtaining exteriorly of the governor for operating said firstvalve to vary said pressure differential; a second valve operable bysaid pressure difierential; and a third valve operable in response toflow through said second valve for controlling the rate of flow of theoperating fluid.

12. In a governor for regulating the rate of flow of a fluid, thecombination of a first valve adapted to produce a pressure differentialin response to flow of the fluid therethrough; means exposed to fluidpressure obtaining exteriorly of the governor for operating said firstvalve to vary said pressure differential; a second valve in series withsa d first valve and operable by said pressure difierential; and a thirdvalve in series with said first valve and in paralel with said secondvalve for regulating the rate of flow of the fluid, said third valvebeing operable in response to flow of the fluid through said secondvalve.

13. In a governor for contro ling the rate of flow of fluid, thecombination of: a main valve for regulating thevrate of flow of thefluid; a pilot valve in parallel with said main valve so that part ofthe fluid flows through said pilot valve and the remainder through saidmain va ve;

pressure actuable means responsive to flow through said pilot valve foroperating said main valve; a metering valve in series with said main andpilot valves; pressure actuable means responsive to a pressuredifferential across said metering valve for operating said pilot valve;and pressure responsive means exposed to fluid pressure obtainingexteriorly of the governor for operating said metering valve.

14. In a fluid-operated pumping system for wells, the combination of: afluid-operated pump adapted to be installed in a well; supply tubingadapted to convey operating fluid under high pressure downwardly throughsaid well to actuate said pump; production tubing in said well andadapted to convey the discharge from said pump upwardly through thewell; a fluid flow governor disposed in the line of said supply tubingand adapted to control automatically the rate of flow of said operatingfluid therethrough in response to changes in rate of flow of suchoperating fluid to said pump; and means for controlling the operation ofsaid governor automatically in response 15 to variations in the level ofliquid in the well, UNITED STATES PATENTS including a fluid passagecommunicating between Number Name Date the interior of said governor andsaid liquid in 493 774 Howes Mar 21 1393 the wellat a point adjacent tosaid governor. 1:976:82) wettstegn 1934 5 2,119,736 Coberly June 7, 1936CLARENCE COBERLY- 2,119,737 Coberly June 7, 193a 2,208,554 Price July16, 1940 REFERENCES CITED 2,266,356 Coberly Dec. 16, 1941 The followingreferences are of record in the 2277746 Downs Man 31, 9 file of thlspatent: 2,333,903 Coberly Jan. 11, 1944

